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October 19, 2024 - Peak Autumn Colors South of Lake Superior
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Autumn leaves around Lake Superior were blazingly colorful on October 18, 2024, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this true-color image.
The brightest colors light up the forests of northern Wisconsin and Michigan’s Upper Peninsula, both located along the southern shore of Lake Superior, which is the northernmost lake. Both islands in Lake Superior—the large Isle Royale and the small Michipicoten Island—also show peak color. Further north, the forests of Canada show color but not as brightly. It is likely that the deciduous trees (those that drop their leaves in winter) are past peak, but the duller color may also suggest that the forests contain an abundance of conifers, which don’t change color in the autumn.
The changing of leaf color in temperate forests involves several causes and reactions, but the dominant factors are sunlight and heat. Since temperatures tend to drop sooner and sunlight fades faster at higher latitudes, the progression of fall color changes tends to move from north to south across North America, usually beginning in mid-September and ending in mid-November.
Weather also affects the range and intensity of colors. If the weather stays above freezing, it is easier for anthocyanins (pigments) to form. Dry weather, which increases the sugar concentration in sap, also increases the amount of anthocyanin. So, the brightest autumn colors occur when dry, sunny days are followed by cool, dry nights.
Image Facts
Satellite:
Terra
Date Acquired: 10/18/2024
Resolutions:
1km (73.3 KB), 500m (218.3 KB), 250m (445.6 KB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
Autumn leaves around Lake Superior were blazingly colorful on October 18, 2024, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this true-color image.
The brightest colors light up the forests of northern Wisconsin and Michigan’s Upper Peninsula, both located along the southern shore of Lake Superior, which is the northernmost lake. Both islands in Lake Superior—the large Isle Royale and the small Michipicoten Island—also show peak color. Further north, the forests of Canada show color but not as brightly. It is likely that the deciduous trees (those that drop their leaves in winter) are past peak, but the duller color may also suggest that the forests contain an abundance of conifers, which don’t change color in the autumn.
The changing of leaf color in temperate forests involves several causes and reactions, but the dominant factors are sunlight and heat. Since temperatures tend to drop sooner and sunlight fades faster at higher latitudes, the progression of fall color changes tends to move from north to south across North America, usually beginning in mid-September and ending in mid-November.
Weather also affects the range and intensity of colors. If the weather stays above freezing, it is easier for anthocyanins (pigments) to form. Dry weather, which increases the sugar concentration in sap, also increases the amount of anthocyanin. So, the brightest autumn colors occur when dry, sunny days are followed by cool, dry nights.
Image Facts
Satellite:
Terra
Date Acquired: 10/18/2024
Resolutions:
1km (73.3 KB), 500m (218.3 KB), 250m (445.6 KB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
